y'=(2/x)y + x^2letu=y/x^2du/dx = (-2y/x^3 + y'/x^2)= -2u/x +y'/x^2y'= x^2.du/dx + 2xu/y'=(2/x)y + x^2x^2.du/dx + 2xu = 2xu + x^2du/dx = 1u= x+Cy/x^2 = x+Cy= x^3 +Cx^2
